A parking assistance system assists the driver in parking a vehicle. The assistance system measures a parking space as the vehicle travels by, and subsequently guides the driver into the measured parking space. The guiding may occur in a passive form, in which the driver receives steering angle instructions and starting and stopping commands which are transmitted via a human-machine interface (HMI). For active automatic guiding, the parking assistance system takes over transverse and/or longitudinal guiding of the vehicle, and the driver receives only starting and stopping instructions, for example.
In practice, the situation may often occur that two parking spaces, one immediately behind the other, are present. FIG. 1 explains such a situation, using the example of two perpendicular parking spaces. A vehicle 100 travels past objects 102 and 104 which border parking spaces. An available parking space 106 is measured, identified as a suitable parking space, and offered to the driver via the HMI. Since in accordance with regulatory requirements a parking assistance system may generally be activated only at a standstill, the driver must first bring vehicle 100 to a stop. This generally does not occur until a position 108 due to a certain reaction time of the driver and a braking distance. However, at this position the parking assistance system has already detected parking space 110. The driver now expects to park in parking space 106, but the system unexpectedly guides him into parking space 110. Due to relative position 108 of vehicle 100 with respect to parking space 110, this results in a parking operation having short stops during backing, wide swings, etc., which is atypical for human drivers and which often is not readily accepted by the driver (and possibly other motorists).
Similar problems may also arise for two or more parking spaces immediately adjacent to one another, in particular (but not exclusively) for perpendicular parking spaces. It is conceivable to provide a complex HMI which indicates to the driver the identified parking spaces, so that the driver is able to select one of the parking spaces. Such a system could possibly require a complicated graphical display for illustrating the plurality of parking spaces in the surroundings of the vehicle. Such complicated systems are complex in their implementation, and entail correspondingly high costs.